How can you fix your ignition switch in your 1995 GMC sierra if your key won't turn even if you had tried with a new key being cut Can you do this at home How much will it cost to get fixed if you can?

If it has air bags, don't try. If it has a security chip on the keyswitch, don't try. If it doesn't have either, remove the steering wheel and expose the turn signal switch. You should be able to see one or more screws that hold the switch assembly in place. Remove the screws, pull the switch and take it with you to an auto parts retailer. You should be able to get a new keyswitch assembly there. Note that it's only the lock mechanism. You aren't really doing anything to the electrical.